ZeptoBars - RSS feed http://zeptobars.ru/en/ Microelectronics. Die-shots. Artificial intelligence. Lasers. en-us Tue, 10 Jun 2006 04:00:00 GMT Sat, 26 Jul 14 23:12:40 +0400 webmaster@zeptobars.ru 120 10 <![CDATA[OPA627, genuine one this time : weekend die-shot]]> http://zeptobars.ru/en/read/BB-TI-OPA627-opamp-genuine-fake Last time we decapped 2 fake OPA627's from ebay: one was remarked AD744 part, another was unidentified remarked BB part.

Recently reader sent us one more OPA627 from ebay. This chip appeared to be genuine.

Die size 2940x2005 µm.

Fri, 25 Jul 14 21:02:13 +0400
<![CDATA[Milandr 1986VE21 : weekend die-shot]]> http://zeptobars.ru/en/read/milandr-1986VE21

Fri, 11 Jul 14 04:05:32 +0400
<![CDATA[KR580VM80A - getting ready for reverse engineering : weekend die-shot]]> http://zeptobars.ru/en/read/kr580vm80a2 first shoot), so that group of enthusiasts (russian only) would be able to recover schematic from it's layout.

A bit more dirt, but less overetch:

Dark field - metal is clearly visible:

Polarized light - metal and vias are visible:

After metallization etch. Any ideas why polysilicon gone?

Thu, 22 May 14 07:19:08 +0400
<![CDATA[Toshiba TCD1201D - linear CCD : weekend die-shot]]> http://zeptobars.ru/en/read/Toshiba-TCD1201D-linear-CCD
Die size 34814x802 µm.

With this die we've reached JPEG limits, full image would be 80k+ pixels wide, so we'll show beginning and the end of the CCD separately:

We are grateful to Kony for this chip.]]>
Sat, 17 May 14 16:45:25 +0400
<![CDATA[SkyWorks AAT4292 - 7-bit high-side IO expander: weekend die-shot]]> http://zeptobars.ru/en/read/SkyWorks-AAT4292-io-expander-100mA Die size 1193x618 µm.

After metallization etch:

Sat, 03 May 14 03:27:28 +0400
<![CDATA[Phillips PCF8574 - 8-bit I2C port expander : weekend die-shot]]> http://zeptobars.ru/en/read/NXP-PCF8574-i2c-port-expander
Sat, 12 Apr 14 22:50:43 +0400
<![CDATA[Fake audiophile opamps: OPA627 (AD744?!)]]> http://zeptobars.ru/en/read/OPA627-AD744-real-vs-fake-china-ebay Walking around ebay I noticed insanely cheap OPA627's. It's rather old, popular and high-quality opamps, often used in audiophile gear. Manufacturer (Texas Instruments / Burr Brown) sells them 16-80$ each (depending on package & options) while on ebay it's cost was 2.7$, shipping included.

Obviously, something fishy was going on. I ordered one, and for comparison - older one in metal can package, apparently desoldered from some equipment. Let's see if there is any difference.

Plastic one was dissolved in acid, metal can was easily cut:


Remarked "metal can" TI/BB OPA627 chip first. We can see here at least 4 laser-trimmed resistors. Laser trimmed resistors are needed here due to unavoidable manufacturing variation - parts inside opamps needs to be balanced perfectly.

"Chinese" 2.7$ chip. There is only 1 laser trimmed resistor, but we also notice markings AD (Analog Devices?) and B744. Is it really AD744? If we check datasheet на AD744 - we'll see that metal photo perfectly matches one in the datasheet .

What happened here?

Some manufacturer in China put an effort to find cheaper substitute for OPA627 - it appeared to be AD744. AD744 has similar speed (500ns to 0.01%), similar type (*FET), supports external offset compensation. AD744 also support external frequency compensation (for high-speed high-gain applications) but there was no corresponding pin on the OPA627 - so this feature is unused.

On the other hand AD744 has higher noise (3x) and higher offset voltage (0.5mV vs 0.1mV).

So they bought AD744 in the form of dies or wafers, packaged them and marked as OPA627. It does not seems they earned alot of money here - it's more of an economic sabotage. Good thing that they did not used something like LM358 - in that case it would have been much easier to notice the difference without looking inside...

Metal "OPA627" appeared to be some unidentified BB part remarked as OPA627.

Be careful when choosing suppliers - otherwise your design might get "cost-optimized" for you :-)

PS. Take a look at our previous story about fake FT232RL.]]>
Tue, 08 Apr 14 10:38:17 +0400
<![CDATA[SiTime SiT8008 - MEMS oscillator : weekend die-shot]]> http://zeptobars.ru/en/read/SiTime-SiT8008-MEMS-oscillator-rosnano SiTime SiT8008 is a programmable MEMS oscillator reaching quartz precision but with higher reliability and lower g-sensitivity. Also SiTime is one of companies who received investments from Rosnano - Russian high-tech investment fund.

Photo of MEMS die puzzled us for quite some time. Is it some sort of integrated SAW/STW resonator?

The trick is that to reach maximum Q-factor (up to ~186'000 according to patents) MEMS resonator must operate in vacuum. So they package resonator _inside_ the die in hydrogen atmosphere, then anneal it in vacuum so that hydrogen escapes through silicon. So we see here only a cap with contacts to "buried" MEMS resonator. We were unable to reach the resonator itself without x-ray camera or ion mill.

MEMS die size - 457x454 µm.

Thankfully relevant patents were specified right on the die : US6936491 US7514283 US7075160 US7750758 :)

Digital die contains LC PLL and digital logic for one-off frequency programming and temperature compensation.
Die size - 1409x1572 µm.

Poly level:

Standard cells ~250nm techology.
Sat, 29 Mar 14 02:54:16 +0400
<![CDATA[TI TL431 adjustable shunt regulator : weekend die-shot]]> http://zeptobars.ru/en/read/TI-TL431-adjustable-shunt-regulator-linear-supply Die size 1011x1013 µm.

Sat, 22 Mar 14 20:25:06 +0400
<![CDATA[TI LM393 - dual comparator : weekend die-shot]]> http://zeptobars.ru/en/read/TI-LM393-dual-comparator Die size 704x748 µm.

Tue, 18 Mar 14 13:34:46 +0400